package com.hmdp.service.impl;

import cn.hutool.core.bean.BeanUtil;
import com.baomidou.mybatisplus.core.conditions.query.QueryWrapper;
import com.baomidou.mybatisplus.extension.conditions.query.QueryChainWrapper;
import com.hmdp.dto.Result;
import com.hmdp.dto.UserDTO;
import com.hmdp.entity.Follow;
import com.hmdp.mapper.FollowMapper;
import com.hmdp.service.IFollowService;
import com.baomidou.mybatisplus.extension.service.impl.ServiceImpl;
import com.hmdp.service.IUserInfoService;
import com.hmdp.service.IUserService;
import com.hmdp.utils.UserHolder;
import org.springframework.data.redis.core.StringRedisTemplate;
import org.springframework.stereotype.Service;

import javax.annotation.Resource;
import java.security.Key;
import java.util.Collections;
import java.util.List;
import java.util.Set;
import java.util.stream.Collectors;

/**
 * <p>
 *  服务实现类
 * </p>
 *
 * @author 虎哥
 * @since 2021-12-22
 */
@Service
public class FollowServiceImpl extends ServiceImpl<FollowMapper, Follow> implements IFollowService {


    @Resource
    private StringRedisTemplate stringRedisTemplate;

    @Resource
    private IUserService userService;

    @Override
    public Result follow(Long followUserId, Boolean isFollow) {

        //获取登录用户
        Long userId = UserHolder.getUser().getId();

        //判断关注还是取关
        if(isFollow)
        {
            //关注则添加
            Follow follow=new Follow();

            follow.setUserId(userId);
            follow.setFollowUserId(followUserId);
            boolean isSuccess = save(follow);

            if(isSuccess)
            {
                //把关注的用户id放入redis
                String  key="follows://"+userId;

                stringRedisTemplate.opsForSet().add(key,followUserId.toString());
            }


        }
        else
        {
            //取关
            boolean isSuccess = remove(new QueryWrapper<Follow>()
                    .eq("user_id", userId)
                    .eq("follow_user_id", followUserId));
            if(isSuccess)
            {
                //把取关的用户id从redis中移除
                String  key="follows://"+userId;
                stringRedisTemplate.opsForSet().remove(key,followUserId.toString());
            }

        }

        return Result.ok();
    }

    @Override
    public Result isFollow(Long followUserId) {

        //获取登录用户
        Long userId = UserHolder.getUser().getId();


        //查询是否关注
        Integer count = query().eq("user_id", userId)
                .eq("follow_user_id", followUserId).count();

        //判断

        return Result.ok(count>0);
    }

    @Override
    public Result followCommons(Long id) {

        //获取当前登录用户的id
        Long userId = UserHolder.getUser().getId();
        //当前用户的key
        String key1="follows:"+userId;

        //查看用户的id
        String key2="follows:"+id;

        //利用redis取交集
        Set<String> intersect = stringRedisTemplate.opsForSet().intersect(key1, key2);

        if(intersect==null||intersect.isEmpty())
        {
            //没有交集返回空集合
            return  Result.ok(Collections.emptyList());
        }
        //有交集，将String转为Long
        List<Long> ids = intersect.stream().map(Long::valueOf).collect(Collectors.toList());

        //根据ids查询用户集合，并转换为userDTO格式

        List<UserDTO> userDTOS = userService.listByIds(ids).stream()
                .map(user -> BeanUtil.copyProperties(user, UserDTO.class))
                .collect(Collectors.toList());


        return Result.ok(userDTOS);
    }
}











